Horizontally operable hydraulic valve lifter



May 31, 19604 1.. R. PAPENGUTH 2,938,508

HORIZONTALLY OFERABLE HYDRAULIC VALVE LIFTER Filed June 4, 1959 INVENTOR.

Karen 1? enya/fi ATTORNEY HORIZONTALLY OPERABLE HYDRAULIC VALVE LIFTER Loren R. Papenguth, Orchard Lake, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed June 4, 1959, er. No. 818,071 9 Claims. c1. 123-90 This invention relates to externally fed hydraulic valve lifters and the like in the form of a dashpot device wherein the plunger is hollow and serves as a reservoir for the externally fed fluid, and particularly to such devices which operate in a substantially horizontal direction.

In horizontal or substantially horizontal operation of hydraulic valve lifters, particularly those in which fluid supply to the plunger reservoir is from an external source as by way of communicating ports in the dashpot cylinder and plunger, a problem exists in preventing the fluid from draining out of the plunger reservoir chamber when the external fluid supply is stopped, unless special provision is made for sealing up the plunger and/or maintaining its fluid inlet opposite the upper portion of the reservoir at all times. In the case of horizontally operated hydraulic valve lifters for internal combustion engines it has previously been proposed, therefore, to either key the lifter cylinder or the plunger against rotation, or to provide check valves in their inlet feed ports to prevent such loss of fluid during engine shutdowns. Without some such means for preventing loss of plunger fluid, air will take the place of the fluid leaking from the plunger during the engine shutdown period, and will result in noisy and other improper operation of the lifter upon restarting the engine.

My invention solves this reservoir leakage problem in a very simple and eflicient manner which only very slightly increases the cost of the lifter over that of conventional designs intended for substantially upright operation. In its broadest aspects, my invention amounts to including within the passage means from the external fluid supply to the plunger reservoir chamber a generally helical passage of substantial radius and coaxial with the plunger, one end of this helical passage connecting with the lifter cylinder supply inlet, and the other end terminating in the reservoir chamber.

These and other objects and advantages of my invention will be readily apparent from the following description of two alternative embodiments thereof, having reference to the drawing wherein:

Figure l is a fragmentary sectional view through the valve lifter guide bore of an internal combustion engine showing one form of my improved valve lifter installed therein in operative relation between the usual driving cam and driven push rod.

Figure 2 is a similar view, but showing a modified form of the lifter of Figure 1.

Figure 3 is a fragmentary view similar to Figure 2, but showing part of the plunger in side elevation.

Referring now in detail to the drawing, the hydraulic valve lifter is designated generally by the numeral 1 and includes a rather conventional, generally cup-shaped dashpot or cylinder member, formed of a tube 2 closed at one end by a foot piece 3. Shown also is the conventional engine driven cam 4 operatively engaging the foot piece 3. The outer periphery of the tube 2 is slidably guided in the lifter bore 5 of the engine crankcase or other fixed part 6 of the engine. The cylinder is open at its Patented May 31, 1969 opposite end 7, and slidably fitting the bore 8 of the tube 2 is a generally cup-shaped or hollow plunger 9. The two cup-shaped members are thus slidably interfitted in nesting relation, with the end wall 10 of the plunger and the cylinder end wall or foot piece 3 forming between them a fluid pressure chamber 11. The internal side walls and end wall 10 of the plunger define a reservoir chamber 12 for storage of fluid required to replenish the pressure chamber 11 for that which escapes therefrom by leakage past the plunger in operation. Means providing a connection between these two chambers for accommodating fluid flow from the reservoir chamber into the pressure chamber, while restricting fluid flow therebetween in the opposite direction, is illustrated in the form of a ball check valve '13 controlling the passage 14 in the end wall of the plunger. Fluid may thus be trapped in the pressure chamber for transmitting thrust from the lifter cylinder to the plunger 9 when movement of the lifter cylinder is eiiected by the cam 4. The plunger return spring 15 acts in compression to bias the plunger outwardly of the lifter cylinder at all times, thereby tending to maintain the pressure chamber volume at a maximum at all times. Mounted on the open end of the plunger is a conventional push rod seat 16 for a push rod 17 which transmits the cam induced plunger motion to the engine valve or other engine part to be actuated by the cam. In the particular construction shown, connecting axial passages 18 and 19 are provided in the push rod seat and push rod for conducting the lifter fluid used (oil) to the other parts (not shown) of the valve operating linkage, and a flow control valve 20 and retainer 21 therefor serve to meter such flow through the push rod, as more fully disclosed in my United States Patent 2,818,050.

Suitable external fluid supply means for the filter is provided including a gallery 22 which may be connected to the engine lubricating pump (not shown), this gallery 22 being open to the lifter bore 5 in the engine. Passage means for connecting this external fluid supply to the plunger reservoir 12 will now be described. The lifter cylinder is provided with an annular external groove 24 of sufficient width to have continuous registry with the gallery 22, and this groove is connected to a port 23 with an internal groove 25 in the bore 8 of the cylinder. The plunger, in turn, has a side port 26 extending therethrough below the push rod seat 16 and registering continuously with the cylinder internal groove 25. In order that the fluid (engine oil) thus entering the plunger to fill the reservoir chamber 12 during engine operation will not drain out during an engine shut-down when the feed pressure in the gallery 22 is discontinued, the passage means into the portion of the reservoir chamber adjacent the end wall 10 of the plunger is continued by a helical passage 27. This helical passage is provided by a generally disk-shaped member 28 of plastic or die cast lightweight metal which is pressed into the hollow plunger to grooves 25, 24, and the other end of this helical passage is in direct communication with the reservoir inwardly of the plunger from the disk. Preferably, the helical groove or passage 27 has a substantial circumferential extent (approximately 360) as shown in order that the reservoir chamber will remain substantially full of fluid in what-f ever relatively rotated position the plunger may assume in the lifter cylinder.

In the modified form of the valve lifter shown in Figure 2, the disk is dispensed with and a helical passage 30 is instead formed as an external groove about the plunger. In order that the groove 30 performs the function of preventing fluid drainage out of that portion of the plunger adjacent the check valve end 10, the plunger side port 31 is located at a distance substantially inward of the lifter cylinder from its side port 26, and out of communication therewith except via the helical groove passage 30. As shown, the end 32 of this helical passage connects directly With the plunger side port 31 and the opposite end 33 of the helical passage connects with the external groove 34 in the plunger which has continuous communication with the internal groove 25 of the cylinder. The push rod seat 35 of the lifter is of conventional form (for use where no lubricant delivery via the push rod 36 is required), and leakage between it and the plunger side walls is sealed by a suitable gasket 37. Operation of this form of the invention is the same as that of the lifter of Figure l,in that fluid (e.g. engine oil) introduced from the gallery 22 via thecylinder port 26 may flow around the helical passage 30 to enter the reservoir 12 at the plunger port 31, but will not drain out by flow in the opposite direction because the opposite ends of the helical passage 30 are axially and circumferentially spaced from each other.

While only two forms of the invention have been disclosed, it is appreciated that numerous minor changes in the construction and arrangement of the parts may be made without departing from the spirit and scope of the V invention as defined in the following claims.

i claim:

1. In a hydraulic valve lifter, slidably interfitting cylinder and hollow plunger members defining a pressure chamber opposite one end of the plunger member and a reservoir chamber interiorly of the plunger member, passage means interconnecting said chambers including means operative to restrict fluid flow from the pressure chamber to the reservoir chamber relative to flow in the opposite direction, and passage means connecting the reservoir chamber to the exterior of the lifter, said last named passage means including a discontinuous passage extending circumfercntially and axially of the reservoir chamber, the opposite ends of said passage being in continuous communication with said reservoir chamber and the exterior of the lifter, respectively.

2. In a hydraulic valve lifter, slidably interfitting, generally cup-shaped cylinder and plunger members having their end walls correspondingly disposed and spaced, and defining a hydraulic pressure chamber between said end walls and a reservoir chamber within said plunger member, passage means beween said chambers for admitting fluid to the pressure chamber from the reservoir chamber, and passage means connecting said reservoir chamher with the exterior of the lifter, said last named passage means including a discontinuous passage extending generally helically of the plunger member, one end of said helical passage being in continuous communication with the exterior of the lifter and the other end being in continuous communication with the reservoir.

3. In a dash pot device having a dash pot defining member and a hollow'plunger operable therein, means for supplying fluid to the dash pot including passage means for fluid flow into the plunger, said passage means including an opening into said plunger from the exterior thereof, and a discontinuouspassage extending helically of the plunger, said passage being connected at one end with said opening and at its other end with the interior of said plunger.

'4. In a hydraulic valve lifter, slidably interfitting cylinder and plunger members, the plunger member having side and end Walls defining a reservoir chamber for fluid adjacent one end of the plunger member, registerable ports in the side walls of said members through which fluid may enter and leave the plunger member adjacent the opposite end of the plunger member, and a disc within and closely fitting the side walls of the plunger member intermediate the ends thereof, said disc defining a helical passage radially remote from the longitudinal axis of the disc and interconnecting said reservoir chamber and said opposite end of the plunger member.

5. In a hydraulic valve lifter, slidably interfltting cylinder and plunger members, the plunger member having side and end walls defining a reservoir chamber for fluid adjacent one end of the plunger member, registerable ports in the side walls of said members through which fluid may enter and leave the plunger member adjacent the opposite end of the plunger member, and a disc transversely Within the plunger member intermediate the ends thereof, said disc having a peripheral external groove coacting with the side walls of the plunger member and interconnecting said reservoir chamber and said opposite end of the plunger member.

6. In a dash pot device having a dash pot defining cylinderand a hollow plunger operable therein, means for supplying fluid to the dash potincluding passage means for fluid flow into the plunger, said passage means including an opening in the plunger irom the exterior thereof, a side port in the plunger inwardly of the dash pot from said opening and a helical external discontinuous groove on the plungerinterconnecting said opening and port.

7. In a hydraulic valve lifter, slidably interfitting cylinder and hollow plunger members defining a pressure chamber within the cylinder member opposite one end of the plunger member and a reservoir chamber within the plunger member for fluid to supply said pressure chamber, said chambers having a connection therebetween accommodating said supply, a side port in the cylinder member, a side port in the plunger member spaced axially of said cylinder member from said cylinder member side port, and a helical discontinuous passage in one of said members connected at one end to one of said ports and at its other end to the other of said ports.

8. In a hydraulic valve lifter having slidably interfitted cylinder and hollow plunger members defining a pressure chamber therebetween at one end and a reservoir chamber within the plunger member for replenishment fluid for said pressure chamber, a side port in the cylinder member and a side port in the plunger member spaced axially of the cylinder member from saidcylinder member port, and an external peripheral discontinuous groove on the plunger member inteconnecting said ports.

9. In a hydraulic valve lifter having generally cupshaped cylinder and plunger members in slidably nested relation, the closed end of the cylinder member defining a pressure chamber for fluid to thrustably support the plunger member and the closed endof .the'plunger member having a check valve controlled aperture through which fluid may enter said chamber from within the plunger member, a side port in the cylinder member and a registering side port in the plunger member through which fluid for replenishing said pressure chamber may enter the plunger member, and a generally disc-shaped member disposed transversely within the plunger member between its said side port andsaid aperture, said disc-shape member having its periphery closely fitting the internal side wall surfaces of the plunger member and coacting therewith to define a helical passage communicating at one end with said plunger member port and the other end with the interior of the plunger member adjacent said aperture.

References ilited in the file of this patent UNITED STATES PATENTS 2,821,970 Line Feb. 4, 19 58 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,938 508 May 31 1960 Loren R. Papenguth It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 35, for "filter" read lifter line 43, for "to a" read by a column 4,, line 13, after "disc" insert disposed Signed and sealed this 13th day of December 1960,,

(SEAL) Amest:

KARL H. AXLINE ROBERT C. WATSON Attesting Oficer Commissioner of Patents 

